https://github.com/sxzz/ast-walker-scope

Traverse Babel AST with scope information.
https://github.com/sxzz/ast-walker-scope

Last synced: 5 days ago
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Traverse Babel AST with scope information.

• Host: GitHub
• URL: https://github.com/sxzz/ast-walker-scope
• Owner: sxzz
• License: mit
• Created: 2022-07-29T10:13:33.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2024-10-29T18:24:18.000Z (about 2 months ago)
• Last Synced: 2024-10-29T18:36:55.716Z (about 2 months ago)
• Language: TypeScript
• Homepage:
• Size: 474 KB
• Stars: 13
• Watchers: 1
• Forks: 0
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE

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README

        
# ast-walker-scope [![npm](https://img.shields.io/npm/v/ast-walker-scope.svg)](https://npmjs.com/package/ast-walker-scope)

[![Unit Test](https://github.com/sxzz/ast-walker-scope/actions/workflows/unit-test.yml/badge.svg)](https://github.com/sxzz/ast-walker-scope/actions/workflows/unit-test.yml)

Traverse Babel AST with scope information.

Inherited from [estree-walker](https://github.com/Rich-Harris/estree-walker).

## Install

```bash

npm i ast-walker-scope

```

## Usage

### Basic Example

For a real example, you can refer to [example.ts](./example.ts)

```ts

import { walk } from 'ast-walker-scope'

const code = `

const a = 'root level'

{

  const a = 'second level'

  let secondLevel = true

  console.log(a, secondLevel)

}

var err = undefined

try {

} catch (err) {

  console.log(err)

}

console.log(a)

`.trim()

walk(code, {

  leave(this, node) {

    if (node.type === 'CallExpression') {

      console.log(`\nLevel: ${this.level}`)

      for (const [name, node] of Object.entries(this.scope)) {

        console.log(

          `variable ${name} is located at line ${node.loc?.start.line}, column ${node.loc?.start.column}`,

        )

      }

    }

  },

})

```

Output:

```

Level: 2

variable a is located at line 4, column 8

variable secondLevel is located at line 5, column 6

Level: 2

variable a is located at line 1, column 6

variable err is located at line 12, column 9

Level: 1

variable a is located at line 1, column 6

variable err is located at line 9, column 4

```

## Typings

```ts

export type Scope = Record

export interface HookContext extends WalkerContext {

  // inherited from estree-walker

  skip: () => void

  remove: () => void

  replace: (node: Node) => void

  // arguments of estree-walker hook

  parent: Node

  key: string

  index: number

  // scope info

  scope: Scope

  scopes: Scope[]

  level: number

}

```

## Sponsors



  

    

  



## Credits

- [@vue/reactivity-transform](https://github.com/vuejs/core/blob/v3.2.37/packages/reactivity-transform/src/reactivityTransform.ts) - almost copy-like referenced

## License

[MIT](./LICENSE) License © 2022-PRESENT [三咲智子](https://github.com/sxzz)